Gas-material separator



July 16, 1963 R. L. LINCOLN GAS-MATERIAL SEPARATOR Filed June 10, 1960 2 Sheets-Sheet 1 F l G.

INVENTOR.

ROLAND L. LINCOLN July 16, 1963 R. L. LINCOLN 3,097,937

GAS-MATER IAL SEPARATOR Filed June 10, 1960 28 2 Sheets-Sheet 2 FIG. 2

FIG. 3

INVENTOR. ROLAND L. LINCQLN United States Patent 3,097,937 GAS-MATERIAL SEPARATOR Roland L. Lincoln, Allentown, Pa., assignor to Fuller Company, a corporation of Delaware Filed June 10, 1960, Ser. No. 35,290 3 Claims. (Cl. 55--292) The present invention relates to the removal of solid matter and other pollutants from gas streams and is concerned more particularly with an improved vent unit for facilitating the control of gas flow through filter-bag dust collectors.

In my copending application Serial No. 834,531, filed August 18, 1959, of which the present application is a continuation-in-part, I disclosed a multiple-chamber dust collector of the filter bag type. In a particular embodiment thereof individual gas-exhaust ducts are provided for each chamber which extend through a gas-material inlet eompartment in the upper region of each chamber, and which open to the clean side of the filter bags through an exhaust aperture in a crown sheet securing the upper ends of the bags. The present invention is especially advantageous when employed with gas-exhaust ducts of this type, and particularly when cleaning of the bags is efiected by sonic generators located centrally in the bag chamber.

In general, the vent unit of the present invention comprises a hood overlying the top wall of a dust-collector chamber, which wall has a vent or exhaust opening in a raised portion thereof. The hood provides a space therebeneath, in the center region of its lower side, for receiving the raised portion oi the top wall and includes hood wall portions sloping downwardly and outwardly to a level below the level of the vent opening in the raised wall portion.

The top wall has a surrounding lip protecting the vent opening and lateral wall portions which slope downwardly and outwardly from the raised wall portion. These wall portions are positioned in spaced relation with the sloping wall portions of the hood to form a peripheral gap or vent opening there-between, at their outer edges, for the free passage of gases.

The hood and top wall may be conical or pyramidal or of any suitable shape which includes downwardly and outwardly sloping lateral portions with those of the hood descending to or below the level of the vent opening or the point of discharge of gases from the lip protecting the vent opening. It is preferable that both walls be of mutual or similar shape, i.e. both conical or both pyramidal, although this relationship is not absolutely necessary.

A better understanding of the invention may be derived from the following description and drawings in which:

FIG. 1 is a vertical sectional View of a preferred form of dust-collecting chamber embodying the exhaust unit;

FIG. 2 is a portion of FIG. 1 on an enlarged scale; and

FIG. 3 is a plan view, partly cut away, of the unit of FIG. 1.

As shown in FIG. 1, the vent unit 1 is arranged as an exhaust unit for a dust collector and is fitted to the upper end of a dust-collector chamber 2 of the type disclosed in my aforementioned application Serial No. 834,- 531. The chamber 2 has a cylindrical side wall 3 closed at its top by a frusto-conical top wall 4. A crown sheet 5 extends across the chamber 2 and is spaced \from the top wall 4 to form an annular gas-material inlet compartment 6' in the upper region of the chamber. The crown sheet 5 has a plurality of downwardly-flanged apertures 7 about which the top ends of a plurality of filter bags 8 are individually secured. The lower ends of the filter bags 8 are secured to a second crown sheet 9, about individual, upwardly-flanged apertures 10 therein.

The crown sheet 5 has a central vent or exhaust aperture 12 which opens to the space between the crown sheets 5 and 9, which space comprises a clean gas chamber 13 about the exterior of the filter bags. A vent or exhaust duct 14 extends from the exhaust aperture 12 through the gas-material inlet compartment 6 and through a vent or exhaust opening 15 in the raised portion of the f-rustoconical top wall 4.

The exhaust duct extends upwardly beyond the wall 4 a sufficient distance to :form a lip 16 about the exhaust opening 15- to keep blown rain drops or other airborne matter from entering the eidiaust opening. The lip 16 is provided with a laterally-extending flange 17 extending outwardly from the lip. However, any suitable form of lip or flange may be used, or if the slope of the top wall is very steep, the lipor flange may be eliminated.

A plurality of peripherally spaced supporting straps 18 are welded or otherwise secured to the cylindrical wall and extend upwardly a distance above the outer edge of the top wall 4 to receive bolts '19 engaging and supporting a peripheral member or ring 20. The ring 20 is spaced from the top wall 4, thereby dividing the peripheral vertical opening 27 to form a peripheral drain opening 22. The ring 20 'has an outwardly-extending flange 23 at its upper edge. A plurality of peripherally-spaced supports 24 are secured on the flange 23, as by welding, and support on their upper ends an upper second ring 25 in spaced relation to the ring 20.

The ring 25 carries a conical hood 26 similarly spaced from the ring 20. The upper ring 25 is welded to the hood on its upper side, and on its lower side to the upper ends of the supports 24, whose length determines the height of the peripheral exhaust opening 27 between the ring 20 and the hood 26 or ring 25. Since the entire unit comprising the hood 26, ring 25, supports 24 and ring 20 is supported on the vertical side wall 3, instead of on the top wall '4, it can carry heavy snow, dust, or other loads on the hood surface without disturbance or distortion of the top wall 4.

When desired, the rings 20 and 25 and the supports 24 may be eliminated by upward extension of the supporting straps 18 for direct engagement with the hood 26, or by other suitable modifications. However, the ring 20 is considered particularly advantageous since it provides the separate drain 22 for drainage of blown-in rain water substantially independently of the passage of gas through the larger peripheral exhaust opening 27 between the ring 20 and the hood 26, while permitting direct support of the unit on the side wall 3.

The sloping wall portion 28 of the conical hood 26 provides a space 29 thereunder, in the hollow of the cone, which receives the raised lip 16. The lip 16 extends upwardly from the top wall 4 to a level even with or above the outermost edge of the sloping wall portion 28 of the hood 26. a

The sloping wall portion 30 of the conical top wall 4 slopes downwardly and outwardly at a substantial angle generally similar to the angle of the sloping wall portion 28. If desired, the exact angle of slope of the top wall and hood may be varied, and, with less advantage, may even be substantially different in their respective angularities to the horizontal, including one or both being at least partially horizontal.

The gas-material inlet compartment 6 has a dusty gas inlet 32 communicating with a supply duct 33. A sonic generator 34 is centrally positioned with respect to the filter bags 8 for periodically generating vibrations to remove dust separated from the gas and collecting on the inside of the bags. As the accumulated dust falls from the inside of the bags it passes through the openings 10 in the lower crown sheet 9 into hopper 35 at the bottom of J the chamber 2 for discharge by any suitable means such as the rotary feeder 36.

In operation, a stream of dusty gas is passed through the duct 33 and inlet 32 into the inlet compartment 6 by a fan or other pressure means (not shown). The dust and gas thus introduced to the inlet compartment pass through the apertures 7 in the crown sheet to the interior of the bags 8. The gases then pass through the fabric of the filter bags, depositing the dust on the inner fabric surface, and proceed to the exterior or clean side thereof in the clean gas chamber 13. The cleaned gases are vented through the exhaust aperture 12, exhaust duct 14 and lip 16 to the space 29 beneath the hood 26, and pass therefrom through any portion of the peripheral exhaust opening 27 to the atmosphere.

The direction of discharge of the cleaned gases will be governed by the local air currents surrounding the vent unit. When little or no substantial air currents are present, the cleaned gases will discharge at random about the full circumference of the peripheral exhaust opening 27. This dispersion eliminates the wisps or traces of extremely fine remaining dusts which are often visible to the naked eye when eflluent gases are discharged in a single column from an ordinary exhaust unit or stack.

If strong, or even extreme winds are present, the cleaned gas will discharge to the downstream side of the hood 26, substantially in the same direction as that in which the wind is blowing at any particular moment. Any wind entering one side of the peripheral exhaust opening is deflected to the side by the conical shape of the top wall 4 and by the surface of the lip 16 and flange 17.

The extension of the lip 16 upwardly into the space 29 beneath the conical hood 26 to a level even with or above the outermost edge of the sloping wall portion 28 causes the lip to act as an obstacle or resistance to air flow directly across the exhaust unit between the upper wall 4 and the hood 26. The frusto-conical nature of the top wall 4 makes it easier for air entering the exhaust unit between the wall 4 and hood 26 to flow off to the side of the unit, after deflection from the surface of the top wall. Therefore, even under the most severe wind conditions, cleaned gas is free to travel through the lip 16 into the space 29 beneath the hood 26, and to How therefrom behind the lip and top wall in the direction of blow of the winds. Any rain which may fall through or may be blown through the peripheral exhaust opening 27 is similarly deflected, and is drained off by the drain opening 22.

No moving parts are necessary to the accomplishment of the purpose of the vent unit, so that the effectiveness of the unit is not affected by sudden changes in wind direction or by jamming of parts, as sometimes happens with swiveling or rotating vents.

The physical appearance of the new vent unit does not identify the installation as a dust collector as does the typical collector stack, and, therefore, frequently is less prominent to a casual observer, or even to a critical observer, since it is often lower in elevation than surrounding equipment. In view of recent and continuing stringent regulations for air pollution control, it is advisable to avoid even the suggestion of dust emission, even when the efficiency of the collecting unit is superior to that required by local regulations.

A particularly important effect of the new vent unit is its ability to attenuate, dampen, or deaden the sound produced by the sonic generator. The term sonic generator is used herein to include all generators for emitting waves of effective cleaning frequencies, regardless of the capability of human ears. However, the peculiarly effective location of the sonic generator in the central region of the filter-bag chamber, as disclosed herein, frequently results in the direct emission or reflective emission of audible sound waves, including stray overtones or beats, through the opening 12, duct 14 and lip 16. In such cases, the vent unit of the present invention forces repeated reflection of the audible noise back toward the source, instead of allowing its direct, or substantially direct escape as in other vent units. Conical, pyramidal, or similar upwardly-converging forms of hoods 26 above the lip 16 are particularly effective in this service since they will tend to focus the reflecting sound waves back toward a point within the lip 16, the duct 14 or the clean-gas chamber 13, depending upon the angle between the surfaces of the conical or pyramidal hood.

Any residual noise which escapes laterally from between the lip 16 and the hood 26 is largely dissipated by repeated reflection between the hood and the top wall 4, so that the surrounding area is not disturbed by the periodic operation of the sonic generators 34.

It is to be understood that the vent unit of the present invention is applicable not only to the exhaust of gases, but also may serve as a gas intake, when desired.

Although the invention has been described using an embodiment of only a single vent opening in the top wall of the dust-collector chamber, it is to be understood that a plurality of such vent openings may be provided, if desired; also that various other changes may be made in the invention as described without departing from the spirit of the invention or sacrificing the advantages thereof.

I claim:

1. A vent unit for a gas-material separator or the like, said separator comprising a side wall and a top wall having a raised portion in the central region thereof, said raised portion of the top wall having a vent aperture, a hood spaced above said top wall to provide a space therebetween, said hood extending substantially over the full area of said top wall, the space between the outer edge of the hood and the outer edge of said top wall forming a peripheral vent opening for the free flow of gases therebetween, and a generally vertically-extending annular member in said peripheral vent opening and extending peripherally thereof, said annular member being substantially aligned with the side wall of the separator and spaced from the top wall thereof to form a drain opening between said member and said top wall.

2. A gas-material separator comprising a chamber having a top wall, a crown sheet spaced from said top wall and extending across the chamber to form with said top wall an inlet compartment, means for introducing a gasmaterial mixture into said inlet compartment, said crown sheet having openings therein, material filtering bags having their upper ends secured about said openings, said crown sheet having an exhaust opening centrally positioned therein and communicating with the space in the chamber surrounding the bags, an exhaust aperture in said top wall, an exhaust stack communicating with the exhaust opening in the crown sheet and extending through said inlet compartment to communicate through the exhaust aperture in the top wall with the space surrounding the bags, a hood overlying and spaced above the top wall, said hood having its highest point above the central area of the outlet of said exhaust stack and sloping downwardly therefrom, said top wall having a raised portion including the exhaust aperture thereof, the space between the outer edge of the hood and the outer edge of said top wall forming a peripheral exhaust opening for the free flow of gases therebetween, and a sound generator in said chamber for inducing dust-removing vibrations in the filter bags, said sound generator being positioned beneath said exhaust opening and centrally with respect to the cross- F sectional area of the chamber.

3. A gas-material separator comprising a chamber having a gas inlet and a gas outlet, filter media interposed in the path of flow of gas from said inlet to said outlet, said chamber having a top wall having a raised portion in the central region thereof, said raised portion of the wall having a vent aperture, supports extending upwardly from the side wall of said chamber, a hood spaced above said top wall to provide a space therebetween, said hood being supported by said supports and extending over substantially the full area of said top wall, the space between the outer edge of the hood and the outer edge of said top wall forming a peripheral vent opening 01 the free flow of gases therebetween.

References Cited in the file of this patent UNITED STATES PATENTS Ruemping Aug. 3, 1880 Wohlfert Nov. 16, 1886 Iles May 31, 1892 McVeety Nov. 22, 1904 

1. A VENT UNIT FOR A GAS-MATERIAL SEPARATOR OR THE LIKE, SAID SEPARATOR COMPRISING A SIDE WALL AND A TOP WALL HAVING A RAISED PORTION IN THE CENTRAL REGION THEREOF, SAID RAISED PORTION OF THE TOP WALL HAVING A VENT APERTURE, A HOOD SPACED ABOVE SAID TOP WALL TO PROVIDE A SPACE THEREBETWEEN, SAID HOOD EXTENDING SUBSTANTIALLY OVER THE FULL AREA OF SAID TOP WALL, THE SPACE BETWEEN THE OUTER EDGE OF THE HOOD AND THE OUTER EDGE OF SAID TOP WALL FORMING A PERIPHERAL VENT OPENING FOR THE FREE FLOW OF GASES THEREBETWEEN, AND A GENERALLY VERTICALLY-EXTENDING ANNULAR MEMBER IN SAID PERIPHERAL VENT OPENING AND EXTENDING PERIPHERALLY THEREOF, SAID ANNULAR MEMBER BEING SUBSTANTIALLY ALIGNED WITH THE SIDE WALL OF THE SEPARATOR AND SPACED FROM THE TOP WALL THEREOF TO FORM A DRAIN OPENING BETWEEN SAID MEMBER AND SAID TOP WALL. 